Behind Closed Doors
by MonMacabre
Summary: Marinette has suspected for awhile, but now she is certain. Beneath the mask, Chat Noir is no other than the icily beautiful Felix Agreste.
1. Chapter 1

It's an unusual feeling, the cool pressure of a gun barrel against your temple.

You know that at any moment your life can slip away, your heart stop pounding in your chest.

Marinette's breathing was already shortening, adrenaline making every nerve sizzle and burn. In stark contrast, the pistol in the masked man's hand felt icy.

Marinette knew a thing or two about wearing masks. They blurred your features, gave you a new identity, and could burden you with completely different responsibilities.

Marinette was burdened with considerable responsibilities.

One of said responsibilities, was protecting people from their darkest selves. Giving them a guiding light when they were lost.

The man holding a pistol to her forehead and hiding behind a black balaclava was most certainly lost.

Marinette made sure to keep her voice calm when she addressed him. "Why do you intend to shoot me Monsieur?"

The man's hand shook but didn't recede into the shadows of his jacket. His voice sounded raw, "B-because you remind me of everything I hate. The… person who ruined my life."

Marinette closed her eyes in thought. "I see." She turned around so the barrel was trained right between her eyes. She met the stranger's gaze. "Then shoot me."

The man gaped, "What?"

Her voice remained steady, "go ahead and kill me."

His finger pressed down on the trigger and Marinette Dupain-Cheng sucked in one last breath of air.

Before disarming him in one smooth and practiced movement, snapping back his wrist and catching the pistol in a her hand.

He moved into a standard defensive position, eyes narrowing hatefully, "I can still kill you little girl. I'm still more powerful than you."

Marinette sighed. "Get over it already."

* * *

She decided to leave his unconscious form slumped against a brick wall before leaving for home.

Walking down the moonlit street, she tucked the handgun in her pink purse, right beside her kwami.

Said kwami raised depthless blue eyes. "Shouldn't you have the police pick him up?"

Marinette smiled, hearing Tikki's sweet voice was such a relief. Sure she had near death experiences regularly, but that was in magical spandex and bearing a different name. Every muscle in her body felt tense, and adrenaline pumped her veins with heat.

She pulled out her cellphone, "Good thinking Tikki."


	2. Chapter 2

Adrien Agreste had been sitting forlornly in his limo when he saw Marinette Dupain-Cheng exiting the small alleyway, her doll like features grim. He smiled and rolled down the window, about to call her name in greeting when his eye caught on glinting steel.

His heart stopped as his mind processed what little could be seen in the dark. In her delicate hand Marinette held a sleek revolver like it was a school standard pencil. He gaped when she casually tucked it away in her handbag.

Marinette continued on her way with what could very well be a murder weapon, childish pigtails swaying cheerfully.

Adrien gulped. Could his kind hearted classmate have been hiding a darker, more sinister side all along? Was his school desk the only thing separating him from a cold killer?

Did a school desk offer any protection from the force that was Marinette Dupain-Cheng?

* * *

"Adrien respectfully requested you be present at dinner," Nathalie lied, his request had most certainly _not_ been respectful, and It wouldn't have bothered Nathalie if the stream of anger had come from anyone else.

 _Adrien is always so level headed. Something must be bothering him._

Monsieur Agreste shook his head. "Tell Adrien I'm currently occupied."

"Are you?"

Gabriel's eyes were cold steel, "It's been some time since an akuma attack, has it not?"

"Indeed, sir." The man was obsessed. Every moment he didn't spend pouring over his work was spent in the room packed with butterflies.

Gabriel inquired,"Was that all you wished to tell me or was there something else?"

Nathalie hesitated, than laid a news article on Gabriel's tasteful desk.

Gabriel didn't reach for it. He leaned back in his chair, avoiding it as much as possible. "You know I prefer you send any information digitally, Nathalie-"

"Sir."

"-It's not hard, really. In Fact, I'd say finding any text electronically these days is simply a matter of-"

" _Sir."_

Gabriel Agreste paused, finally meeting her gaze with obvious reluctance, "Yes, Nathalie?"

"Your son has has returned."

Gabriel picked through his pile of paperwork nonchalantly, "Adrien?"

"No." Nathalie let the taboo name escape her mouth, "Your eldest. Felix"

She stepped back and awaited the explosion.

But Gabriel only reached for the gazette and read it's headline, his eyes raking over the lines with growing distress.

Nathalie observed as Gabriel Agreste's shoulders heaved with silent sobs. It would seem even the most pristine of gods could be knocked from their altar.

What a shame.


	3. Chapter 3

Felix Agreste woke up with a pounding headache and the stark memory of blue eyes. He hadn't seen eyes so blue since Coccinelle. They were eyes he hated.

Something nudged his leg and he groggily to took in his surroundings. He was tied to a cold chair in a poorly lit room. A tall mirror adorned one of the white washed walls, but Felix knew better. He gave the mirror one of the most cutting looks in his arsenal.

A man cleared his throat, and Felix startled, realizing someone was sitting across the table from him.

The stranger cleared his throat. "I'm going to ask you a few questions Felix. My name is Officer have been arrested for first degree murder."

Felix's arm's strained against their plastic bindings. If he had the power of destruction, they'd be dust in seconds.

His voice was a harsh growl, "That's bullshit. The girl got away."

 _And she knocked me over the head with my own gun._

Officer Raincomprix nodded, "Thankfully, you are correct. Your victim called us right after managing to escape. Somehow…

"But your most culpable crime was the successful murder you commited six years ago." Officer Raincomprix pulled out a heavy file labeled with Felix's name. "It would seem, that under the guise of Chat Noir, you committed the manslaughter of one Bridgette Cheng."

Silence.

Felix said nothing. The bindings at his wrists were cutting through his skin after pulling and tugging desperately, and he didn't want to hear this. He would never want to hear this.

"Why did you kill mlle. Cheng?"

Felix stayed silent.

"Why would you take the _life_ of an _innocent?_ " Officer Raincomprix was growing unprofessionally distressed, and Felix debated telling him so.

Instead, Felix asked, "Does… my family know of my apprehension?"

Officer Raincomprix nodded shakily. "Monsieur Agreste should be arriving shortly." he stood from his chair, probably leaving for a spot behind the one way window. "There will be more questions in the future pertaining to Bridgette Cheng's murder."

Felix closed his eyes, listening to the officer's retreating footsteps. He kept them closed, even when the heavy military issue door closed, leaving the room practically empty.

Felix felt filthy, still clad in the black jacket and pants. The police had taken his mask, or maybe that girl had. It didn't really matter. The baklava had only been an echo of his previous, miraculous mask. The face of Chat Noir.

He wanted it back.

There was a groan as the door was opened once more, and someone sat down where Officer Raincomprix had previously been sitting.

Felix opened his eyes, "Father-"

"I'm not our Father, Felix."

"Adrien?" Felix gaped as the child he once knew stared at him with beryl green eyes.

Adrien's intense expression shifted, and he gave a tentative smile. "Yes." Adrien's voice- it was so low. No longer the lovely lilt of a child but the that of a man.

"It's been some time, has it not?"

"Indeed."

There was a moment of silence, and what seemed like millions of words fluttered on Felix's tongue…

Adrien beat him to the punch, "Why did you leave?"

Suddenly Felix found he had very little to say.

"You left." Adrien's voice was quiet, "And then mother died."

"I-I'm sorry."

"What does it matter if you're sorry?!" The words were biting.

Felix knew he deserved Adrien's anger.

"You left me in that house, all alone."

"You had father…"

Adrien shook his head, "Father changed when mother died. He changed when you _left_ us." Adrien stood from his chair. "I might as well have been living alone for years."

Felix's voice was a murmur, "I had to leave. To- to get away."

Adrien's gilded brows furrowed, "Away from what?"

Felix said nothing.

"Please," Adrien whispered, "I need answers. I feel as though I've been grasping at strings for as long as I can remember. Father won't look at me, speak to me; It's all smoke and mirrors."

Felix looked away in shame. "Some things are best left unknown. Our family history- its hideous Adrien. Father tries to disguise it with pretty fashion and fame. I tried to forget it all together."

Adrien stood from his seat. "What exactly is there to forget Felix?"

Felix closed his eyes. "It's better if you don't know." His wrists felt raw in their bindings, his whole body taut with anxious guilt.

"I see..."

Felix opened eyes to peer at his younger brother. "Adrien?"

Adrien's voice was raw, "So after all the years you've been gone, all you can tell me upon our reunion is that- is that I'm still an outsider? That you're still shrouded in mystery?"

"Adrien-"

"No. I'm tired of all these secrets. If this is the life of an Agreste, I'll just have to become someone else."

Felix froze. What did those words mean exactly?

But Adrien was already leaving, steps quick and pounding as he pulled open the door with unusual strength. He shot Felix one last glance and said, "The bail has been paid, and I can only assume you shall be released soon. Father says you are to return home as soon possible. I suggest you don't."

And then Adrien was gone.

Felix released a breath of hot air into the silence.


	4. Chapter 4

Marinette rose from bed with a groan and a pounding headache. She tried desperately to ignore the piercing sounds of her alarm clock, instead opting to let herself be cloaked in steam and burning water.

Stepping out of the shower, the chill of Parisian autumn nipped at her sides, and she rushed to pull on one of her warmest exclusively pink outfits.

Eyeing the body length mirror, she nodded in satisfaction and pulled the dark bangs from her eyes.

She opened her purse so that a sleepy Tikki could flit in, and raced down the carpeted stairs. "See you soon Maman!"

Sabine Cheng didn't miss a beat, handing Marinette a small parcel containing freshly baked pastries, "Take some lunch mon cherie!"

Marinette stumbled, but managed to stay on her feet, "Right!" She gave her mother one last peck on the cheek before running out the door, "bye Papa!"

Tom Dupain's baritone sounded as the door shut behind her, "Have a great day sweetie!"

Marinette grinned, "Without a doubt."

* * *

Due to a slight navigational mix up, Marinette managed to be a total of fifteen minutes late to Mathematics.

Slipping into the classroom, Marinette murmured her apologies and took the vacant seat beside Alya.

Leaning in conspiratorially, her best friend whispered, "Adrien was asking about you before class started girl."

Marinette's eyes widened comically, "Me?"

Alya chuckled, "yes, you. It would seem sunshine boy couldn't get you off his mind all morning."

Marinette's gaze wandered down down the buttery locks of Adrien Agreste. Perfectly coiffed and shining in the sunlight, Marinette yet again wondered if his hair was somehow magically enhanced.

Probably sensing her insistent stare, Adrien turned around his seat. Green eyes met bright azure, and suddenly Marinette's cheeks flooded with warmth.

Flustered, Marinette tried her best to act normal. She sent him a small, awkward wave and an equally unnatural smile.

Adrien returned the wave, (always the perfect gentleman), but his expression was tense, expression wary.

Marinette felt uncomfortable, but didn't back away from his gaze. How could she?

She worried her lip, and asked him, voice hushed, "A-are you alright Adrien?"

Adrien did nothing more than watch her for a few seconds before he turned back around in chair.

Marinette gaped, _he's full on ignoring me now?!_

Alya's face relayed Marinette's unease perfectly, "Did something happen to Adrien?"

Marinette shook her head. She had no idea… but couldn't help but feel she was to blame.

* * *

The bell rang, announcing the school day's end after a long day of stress and little academic success.

Trudging home, Marinette felt a new weight settle in her chest. It curled her shoulders and cast her gaze downwards.

All day- all day Adrien had watched her with that terrible _wariness_. He seemed to recoil from each of her advances, as if they hadn't been friends all these months.

Hadn't they?

From her bedroom window, she saw him enter his limo, shoulders sagging. She _wanted_ to go to him before he left… but she couldn't bear to break whatever they had left.

She had been so sure of herself this morning. That past Marinette had thought that the day would bring amazing things.

She hadn't imagined that this day would mark the beginning of such a hollowing loneliness.


	5. Chapter 5

Adrien sat in his room, rifling through his knowledge of Marinette Dupain-Cheng.

It was unnerving how every memory of her depicted her as something completely innocent and sweet. Certainly she was headstrong and temperamental at times, but it was only with good intentions that she had grown aggravated.

He ran a hand through his hair, racking his brain for anything, any evidence of Marinette having a violent side to her. Seeing her give him sad eyes all day had rattled something inside him. Was she trying to cover up for herself?

... But that would mean Marinette knew what he had witnessed.

Was it really all just an act? If that were the case, she was a superb actress. And if she though Adrien might know too much… then he might very well be in danger via pastel pink.

Adrien realized that while he was no match for her handgun, Chat Noir very much was. He spotted Plagg lazing on his bed and approached it, features grim.

"Palgg! Claws-" the doorbell to the Agreste Mansion rang out, bright and echoing. Swearing a colorful arrangement of profanity, he raced for the entrance gate, feet pounding against the marble floor. He knew who had arrived, had suspected they would come after all.

They couldn't have come at a worse time.

Once he reached the outdoors, he slowed his walk to a leisurely pace. Taking his time to reach the tall gate and meet the storm gray eyes of his brother.

Felix gulped, "Adrien, I-"

But Adrien felt indifferent. "Did I not I tell you to leave? Take what little belongings you have in your possession and leave the mysterious family history behind."

"But-"

"I don't care anymore Felix, whatever it is you're hiding, I'm sure we'll all be safer uninvolved. I don't want you back In my life, so please…" His voice faltered when he saw a new, more adorable presence stumble up to the gate.

He'd been too slow- to get Felix to leave, to transform, to do anything before Marinette Dupain-Cheng had reached him.

She panted for a minute, bent over and catching whatever breathe she could manage before standing back up and sending him an adorable little wave.

"Hey, Adrien."

* * *

Her voice was so terribly meek, but she supposed it was unavoidable. Even when he seemed to hate her, those beryl green eyes set a storm of butterflies a flight in her stomach.

Adrien, standing behind the mansion's gate as if to block himself from her, had gone terribly pale upon Marinette's arrival.

"...Hi, Marinette."

There was small grunt from her left and she suddenly realized that there was a stranger standing beside her.

Marinette stepped back a bit, examining his features, "I'm sorry- but you look terribly familiar. Do you think we might have met before?"

The stranger said nothing, only glanced down at her outstretched hand. The young man had a pale complection, with the sharp angular features of a runway model and storm gray eyes.

His voice was compassionless, "You don't remember who I am?"

She shook her head, sheepish smile in place, "I'm afraid not, but I'm sure your name is on the tip my tongue… I can be really absent minded sometimes." she giggled self consciously, rubbing the back of her neck.

The boy smiled politely, though it didn't reach his eyes, "That's quite alright mademoiselle." Marinette smiled in relief, glad to meet someone gracious- "I understand it's difficult to recognize fame when one has been living under a rock."

Beside them, Adrien scoffed, a sound Marinette had never before heard him produce. "Please Felix. If anyone has been hiding under a rock, it would be you. You're hardly the face of Agreste designs these days, especially in _that_ getup."

The other boy shot Adrien a cutting smile, "Now Adrien, that's no way to talk to family."

Marinette froze. _What?_

Adrien cleared his throat, leaning against the gate that barriered them from him. "Marinette, meet my brother, Felix Agreste."

Marinette looked between, comparing the angelic features that she knew so well, to the icier, more mature ones. The resemblance was undeniable.

Her breath came faster, "Br- brother?"

Felix Agreste gave a smirk that could rival that of a certain black cat.

Lightning struck her as the revelation blossomed in Marinette's mind.

Was Felix Agreste her Chat Noir?


End file.
